The present invention relates to dryer vents and building air vents, and more particularly relates to a vent apparatus mountable to a building wall for passing air to the outside of a building, with the present vent apparatus including features preventing birds and animals from entering the vent, and discouraging them from building nests in or on the vent. A scope of the present apparatus is not believed to be limited to only dryer vents, and instead the present invention is believed to be applicable to any air outlet from a building, such as bathroom fans, kitchen fans, furnace air outlets and other air outlets.
Dryer vents on a building's exterior walls are attractive to animals, especially birds, because they are warm, often sheltered, and often in hidden or non-busy locations. However, the presence of birds, animals and/or their nests can restrict air flow and/or cause debris to accumulate in the air outlet passageway, creating fire and/or smoke hazards and otherwise adversely affect a dryer's operation. It can also lead to a foul smell and unsanitary conditions. Notably, these are the kind of problems that are rarely recognized ahead of time, but instead are usually found when more serious issues arise.
Some bird/animal restricting vent devices exist or have been proposed, but known vent devices are undesirably complicated and/or expensive and/or not as durable and robust as desired and/or do not function effectively. One such device (see Vagedes U.S. Pat. No. 6,772,538) includes a rotating paddlewheel or fan blade that purportedly blocks entry of birds and also creates movement frightening any bird or animal away. However, the rotating paddlewheel adds considerable expense to the device based on part cost. Also, as a practical matter, it doesn't take much to cause the paddlewheel to hang up or stop moving freely, resulting in lack of function, warranty (if the problem is even noticed), and potentially other in-service problems related to lack of function and/or poor air flow. Most homeowners will not realize that the paddlewheel has stopped moving, nor that his/her dryer has lost efficiency, until a serious problem arises with the dryer. Also, there are questions about whether the paddle-wheel's movement will actually frighten birds after the birds become desensitized over a period of time.
Another such device, shown in Vanden Bosch U.S. Pat. No. 7,988,544 includes complexly shaped parts with overlapping flanges (see FIGS. 3a and 3b). The parts complexity (see FIGS. 4, 5a, 6a), requires that they he injection molded of plastic, which potentially results in high tooling and manufacturing cost. Also, the up-facing lower flange of the door and also a top of the housing (see FIG. 3a) provides semi-horizontal surfaces that a bird or animal (or wasp) could potentially start to build a nest on, such as if the vent is not used for a period of time. Notably, the door's movement will not tend to dislodge any partially-built nest (see FIG. 3b). Still further, the part's complex shapes and overlapping flanges potentially lead to clearance and tolerance problems in the assembled product, such that considerable assembly time and quality control effort must be made to assure the door will move as intended both during initial manufacture and also during extended use in the field.
An improvement is desired that provides savings and improvements in terms of simpler and lower cost parts, lower capital investment, increased efficiency and ease of installation, robustness, safety, and improved long term operation.